Polyamide 6 With Siloxene or CaSi₂: Is Nanofiller Better?

Siloxene, a 2D material based on silicon, was successfully synthesized from CaSi 2 in a medium scale quantity. Materials were thoroughly described by X‐ray diffraction, infrared and Raman spectroscopies, and scanning electron microscopy. Here, we report their usage as polyamide 6 (nano)fillers. (Nano)composites were prepared by in situ ring‐opening intercalation polymerization of ε‐caprolactam initiated by ε‐caprolactam magnesium bromide with N,N′‐isophthaloyl‐bis‐(ε‐caprolactam). Polymer content, viscosity‐average molar mass, crystallinity, mechanical properties, thermal stability, and calorimetry measurements were comprehensively evaluated. Homogeneity of fillers' dispergation was observed by transmission electron microscopy. The performed analyses showed that mechanical properties can be significantly improved by the addition of either filler; CaSi 2 had a greater impact on tensile results (ultimate strength increase up to 42% ± 7%), siloxene on impact test results (impact strength increase up to 24% ± 12%). Thermal stability and melting temperature are comparable to the unfilled sample. Unsurprisingly, the addition of fillers increased the crystallization temperature as they act as nucleating agents. Fillers were generally dispersed well up to 1 wt%; however, certain agglomeration was observed.